This invention relates to a novel composition comprising a complex chemical compound of calcium O-methyl-O-(2,2-dichlorovinyl)phosphate with O,O-dimethyl-O-(2,2-dichlorovinyl)phosphate which will be referred briefly as CAVP hereinafter throughout the specification, and a specifically selected thermoplastic resin, said composition being highly effective for anthelmintic purposes through oral administration for domestic animals and poultry and representing a remarkably low mammalian toxicity.
The specifically selected thermoplastic resin in the above sense resides in a copolymer obtainable by copolymerizing 30 to 60 wt. parts of a conjugated diene compound, 70 to 40 wt. parts of at least a monomer which is selected from the group consisting of monovinyl compounds copolymerizable with the aforementioned diene compound and 0.5 - 5 wt. parts of a crosslinking agent. More specifically, the composition of the present invention is an anthelminitic for oral administration of domestic animals and poultry with low mammalian toxicity, as obtained by uniformly mixing CAVP to aforementioned copolymer or to the mixed resin compound of aforementioned copolymer with at least one of the thermoplastic resins selected from the group consisting of polymethyl methacrylate, polyvinyl chloride, polyvinyl acetate, polystyrene and a copolymer of ethylene and vinyl acetate.
The conjugated diene compound which is utilized as a monomer component in the present invention is selected from the group comprising butadiene, isoprene, chloroprene and the like.
The monovinyl monomer which is copolymerizable with aforementioned diene compound is selected from the group consisting of ethylene, propylene, styrene, vinyl chloride, vinyl acetate, acrylonitrile, methyl acrylate, vinyl butyl ether, vinylidene chloride, methacrylonitrile, .alpha.-methylstyrene and methyl methacrylate.
The active ingredient of the composition of the present invention, CAVP, is known as an organo-phosphorous insecticide having many excellent characteristics as disclosed in the Japanese Patent Publication Sho-42-10399, and the utilization of CAVP as an anthelmintic for warm-blooded animals has been applied for a Japanese patent under Patent Application Sho-43-26561.
According to the said Japanese Patent Application, the chemical compound is claimed to be low-toxic to warm-blooded animals and to have an excellent anthelmintic effectiveness.
Having continued researches for improvements in the utilization of CAVP as anthelmintic to be orally administrated to warm-blooded animals, we have now found that the composition according to the present invention is very low-toxic and superior for control of the helminths in warm-blooded animals without giving any adverse effects to such animals.
It is generally known that organo-phosphorous compounds have a high lethal effect against helminths in animal bodies. However, owing to their high mammalian toxicity, a large oral dose of them will mostly give harmful or unhealthy effects to the animals with occasional death due to their rapid adsorption in stomachs or intestines of the animals. Under occasions owing to their rapid decomposition or to their rapid adsorption in the intestines, small oral dose of the compounds may sometimes be inefficient in controlling the helminths parasiting mainly in intestines. Moreover, the warm-blooded animals are very keen in the taste and odor of the feed and medicines and they are apt to deny to take the feed when containing such animal medicines. Even when they should take the feed, it is sometimes difficult to dose effective amount of the medicine due to their liable vomiting after the administration.